Fructose Content Research Articles

Au nanozyme-based colorimetric sensor array integrates machine learning to identify and discriminate monosaccharides

As different monosaccharides exhibit different redox characteristics, this paper presented a novel colorimetric sensor array based on the glucose oxidase-like (GOx-like) activity of Au nanoparticles (NPs) for monosaccharides identification. AuNPs can use O2, ABTS+•, or [Ag(NH3)2]+ as an electron acceptor to catalyze the oxidation of monosaccharides in different velocity, resulting in cross-responsive signals. The current sensor array can distinguish between different monosaccharides or their mixtures through linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA). Moreover, the glucose and fructose concentrations can be estimated simultaneously using a neural network regression model based on the sensor array. This method shows potential for monosaccharide detection in industrial, medical, and biological applications.

Garlic (Allium sativum L.) Invertase Genes: Genome-Wide Identification and Expression in Response to Abiotic Stresses and Phytohormones

Invertases are involved in plant growth, development, and stress adaptation; however, invertase-encoding genes have not yet been reported in Allium species. In this study, we identified 23 invertase izogenes in garlic (Allium sativum L.): 11 encoding putative neutral/alkaline (AsN/AINV1–11) and 12 acid (6 cell-wall—AsCWINV1–6 and 6 vacuolar—AsVINV1–6) enzymes. Among them, AsN/AINV1, 3, 8–10, AsCWINV2–5, and AsVINV2–6 showed significant transcription in garlic organs (roots, bulbs, pseudostems, leaves, sprouts, and reproductive parts) in a tissue-specific manner, whereas the AsN/AINV4–6, 11, AsCWINV1, 6, and AsVINV1 genes had weak or no detectable expression. Gene promoters contained nine, nine, and sixteen hormone-, stress-, and light-responsive cis-regulatory elements, respectively, and fifteen sites related to transcription factor binding and plant development. Expression analysis revealed that 12 invertase genes strongly transcribed in the roots of A. sativum cv. Ershuizao showed differential expression in the roots and leaves of A. sativum cv. Sarmat exposed to abiotic stresses (low temperature, high salinity, and drought) and phytohormones (abscisic acid and methyl jasmonate), which was significantly correlated with glucose, fructose, and sucrose contents. Our results should further functional analysis of invertases from Allium crops and contribute to the breeding of stress-tolerant varieties.

Innovative antibacterial and antifungal coating films of chitosan/nano zinc oxide/essential oil on grape preservation

The effects of some innovative antibacterial and antifungal coating films of chitosan/nano zinc oxide/essential oil (C-ZNO-EO) on grape preservation for human health were studied during the storage periods on (0, 4, 7, 14, and 16) days. Several evaluation approaches were evaluated such as the bacterial evaluations against the presence of the mesophilic aerobic bacteria. The polyamines evaluation was studied by thin-layer chromatography (TLC) for putrescine and spermidine. Soluble sugars were detected by high-performance liquid chromatography (HPLC) for fructose, glucose, and sucrose. Iron, zinc, and manganese were absorbed by the spectrum spectrophotometer. The antifungal properties have been examined against Botryis cineraa, Aspergillus niger, and Tubingensis. The results reported that the highest mesophilic aerobic bacteria (4.73 Log CFU g−1) was recorded in the control grapes on the 16th day, whereas the lowest level (2.05 Log CFU g−1) was recorded for C-ZNO-EO. The polyamines ranged from 12.18 nmol g−1 FW to 10.1 nmol g−1 FW, and from 21.35 nmol g−1 FW to 16 nmol g−1 FW for putrescine and spermidine during the storage periods, respectively. The grapes treated with C-ZNO-EO achieved the maximum increase in glucose and fructose contents (40.61 and 30.05 μmol/g FW), while grapes treated with chitosan/nano zinc oxide (C-ZNO) achieved the maximum increase in sucrose (0.982 μmol/g FW) compared with chitosan (C) and control treatments at the end of the storage periods, respectively. Using C-NZO-EO treatment had a positive effect on the mineral compositions and the antifungal against Botryis cineraa, Aspergillus niger, and Tubingensis. The innovative antibacterial and antifungal coating film by C-NZO-EO was the best treatment for grape preservation.

Overexpression of a transcription factor MdWRKY126 altered soluble sugar accumulation in apple and tomato fruit

The compositions and contents of soluble sugars highly determine the flavor and quality of flshy fruits. In the present study, we found that the overexpression of transcription factor MdWRKY126 localized on the nucleus enhanced sucrose concentration while decreased fructose and glucose concentration in transgenic apple calli and ripening tomato fruits. To comprehensively understand the effects of the MdWRKY126 on the content of various soluble sugars in apple and tomato fruits, enzyme activities and related essential genes associated with the sugar metabolism and transportation pathway in MdWRKY126-overrexpressed apple and tomato lines were analyzed. The results indicated that the overexpression of MdWRKY126 upregulated sucrose phosphate synthase (SPS) activity and the gene expression levels of SPS and sucrose transporter SUT, which was conducive to a large accumulation of sucrose in fruit cells. Meanwhile, MdWRKY126 overexpression downregulated the activity of enzymes involved in sucrose decomposition including cell wall invertase (CWINV), sucrose synthase (SUSY) and the corresponding gene expressions, as well as inhibited the expression levels of hexose transporter (HTs) and tonoplast sugar transporter (TSTs) that transport hexose into vacuoles, resulting in a reduced hexose level in apple calli and tomato fruit. These findings enrich our understanding of the metabolism and regulation of soluble sugars in apple fruits.

SlZIP11 mediates zinc accumulation and sugar storage in tomato fruits.

Zinc (Zn) is a vital micronutrient essential for plant growth and development. Transporter proteins of the ZRT/IRT-like protein (ZIP) family play crucial roles in maintaining Zn homeostasis. Although the acquisition, translocation, and intracellular transport of Zn are well understood in plant roots and leaves, the genes that regulate these pathways in fruits remain largely unexplored. In this study, we aimed to investigate the function of SlZIP11 in regulating tomato fruit development. We used Solanum lycopersicum L. 'Micro-Tom' SlZIP11 (Solanum lycopersicum) is highly expressed in tomato fruit, particularly in mature green (MG) stages. For obtaining results, we employed reverse transcription-quantitative polymerase chain reaction (RT-qPCR), yeast two-hybrid assay, bimolecular fluorescent complementation, subcellular localization assay, virus-induced gene silencing (VIGS), SlZIP11 overexpression, determination of Zn content, sugar extraction and content determination, and statistical analysis. RT-qPCR analysis showed elevated SlZIP11 expression in MG tomato fruits. SlZIP11 expression was inhibited and induced by Zn deficiency and toxicity treatments, respectively. Silencing SlZIP11 via the VIGS technology resulted in a significant increase in the Zn content of tomato fruits. In contrast, overexpression of SlZIP11 led to reduced Zn content in MG fruits. Moreover, both silencing and overexpression of SlZIP11 caused alterations in the fructose and glucose contents of tomato fruits. Additionally, SlSWEEET7a interacted with SlZIP11. The heterodimerization between SlSWEET7a and SlZIP11 affected subcellular targeting, thereby increasing the amount of intracellularly localized oligomeric complexes. Overall, this study elucidates the role of SlZIP11 in mediating Zn accumulation and sugar transport during tomato fruit ripening. These findings underscore the significance of SlZIP11 in regulating Zn levels and sugar content, providing insights into its potential implications for plant physiology and agricultural practices.

Differences in analytical methods affect the analytical values of soluble solids, free sugar, and organic acid content of strawberries

The present study compares different pre-treatments used to analyze free sugars and organic acids in strawberries. Soluble solid content, free sugars, and organic acid content in strawberries may vary depending on the pre-treatment methods used for analyze. A comparison of freshly squeezed juice and that obtained post freezing and thawing revealed a significant reduction in sucrose content in the once-frozen juice. However, no significant differences were observed in the soluble solids, glucose, and fructose contents. Furthermore, crushed flesh had significantly higher soluble solid, glucose, and fructose levels and lower sucrose content than those of the juice. Crushed flesh exhibited significantly higher citric acid and a lower malic acid content than those in the juice. There was a significant reduction in sucrose content in the freeze-dried samples compared to all other pre-treatments. Contrastingly, citric and malic acid levels were higher in the freeze-dried samples than that in the freshly crushed samples. The sucrose analytical values can be greatly decrease during the pre-treatment process. Therefore, differences in analytical methods should be considered when comparing sucrose content and composition.

Overexpression of VaBAM3 from Vitis amurensis enhances seedling cold tolerance by promoting soluble sugar accumulation and reactive oxygen scavenging.

The VaBAM3 cloned from Vitis amurensis can enhance the cold tolerance of overexpressed plants, but VaBAM3 knock out by CRISPR/Cas9 system weakened grape callus cold tolerance. In grape production, extreme cold conditions can seriously threaten plant survival and fruit quality. Regulation of starch content by β-amylase (BAM, EC: 3.2.1.2) contributes to cold tolerance in plants. In this study, we cloned the VaBAM3 gene from an extremely cold-tolerant grape, Vitis amurensis, and overexpressed it in tomato and Arabidopsis plants, as well as in grape callus for functional characterization. After exposure to cold stress, leaf wilting in the VaBAM3-overexpressing tomato plants was slightly less pronounced than that in wild-type tomato plants, and these plants were characterized by a significant accumulation of autophagosomes. Additionally, the VaBAM3-overexpressing Arabidopsis plants had a higher freezing tolerance than the wild-type counterparts. Under cold stress conditions, the activities of total amylase, BAM, peroxidase, superoxide dismutase, and catalase in VaBAM3-overexpressing plants were significantly higher than those in the corresponding wild-type plants. Furthermore, sucrose, glucose, and fructose contents in these lines were similarly significantly higher, whereas starch contents were reduced in comparison to the levels in the wild-type plants. Furthermore, we detected high CBF and COR gene expression levels in cold-stressed VaBAM3-overexpressing plants. Compared with those in VaBAM3-overexpressing grape callus, the aforementioned indicators tended to change in the opposite direction in grape callus with silenced VaBAM3. Collectively, our findings indicate that heterologous overexpression of VaBAM3 enhanced cold tolerance of plants by promoting the accumulation of soluble sugars and scavenging of excessive reactive oxygen species. These findings provide a theoretical basis for the cultivation of cold-resistant grape and support creation of germplasm resources for this purpose.

Sugar delivery at the tomato root and root galls after Meloidogyne incognita infestation

Root-knot nematodes (RKNs) infect host plants and obtain nutrients such as sugars for their own development. Therefore, inhibiting the nutrient supply to RKNs may be an effective method for alleviating root-knot nematode disease. At present, the pathway by which sucrose is unloaded from the phloem cells to giant cells (GCs) in root galls and which genes related to sugar metabolism and transport play key roles in this process are unclear. In this study, we found that sugars could be unloaded into GCs only from neighboring phloem cells through the apoplastic pathway. With the development of galls, the contents of sucrose, fructose and glucose in the galls and adjacent tissue increased gradually. SUT1, SUT2, SWEET7a, STP10, SUS3 and SPS1 may provide sugar sources for GCs, while STP1, STP2 and STP12 may transport more sugar to phloem parenchyma cells. At the early stage of Meloidogyne incognita infestation, the sucrose content in tomato roots and leaves increased, while the glucose and fructose contents decreased. SWEET7a, SPS1, INV-INH1, INV-INH2, SUS1 and SUS3 likely play key roles in root sugar delivery. These results elucidated the pathway of sugar unloading in tomato galls and provided an important theoretical reference for eliminating the sugar source of RKNs and preventing root-knot nematode disease.

Solid-State Fermentation of Ganoderma lucidum on the Soluble Sugar Metabolism of Three Summer–Autumn Black Tea Varieties

Soluble sugar is one of the important characteristic metabolites contributing to the flavor quality of tea. However, little is known about the changes and metabolic pathways of sugar in summer–autumn black tea varieties during the solid-state fermentation of Ganoderma lucidum. Therefore, this study is aimed at investigating the effects of the solid-state fermentation of Ganoderma lucidum on soluble sugar metabolism in three summer–autumn black tea varieties. In this study, we combined targeted metabolomics technology, gas chromatography-mass spectrometry, and multivariate statistical analysis to reveal the metabolic rules of 13 different sugars in three varieties of summer–autumn black tea under the action of Ganoderma lucidum. Using multivariate statistical analysis, 8 common key sugar differential metabolites were selected from the three groups of samples: D-fructose, trehalose, lactose, maltose, D-galactose, glucose, L-rhamnose, and xylitol. The eight different sugars contributed to the quality difference between Ganoderma lucidum tea and black tea in this study. To better explore the patterns of sugar changes, the metabolic pathways of 13 different sugars were screened and analyzed. The result revealed that the solid-state fermentation of Ganoderma lucidum increased the sweet characteristics and decreased the bitter characteristics of the three summer–autumn black tea varieties. In addition, these results showed that the solid-state fermentation of Ganoderma lucidum could produce lactose in tea, reduce glucose and fructose contents, and increase xylitol content. The solid-state fermentation of Ganoderma lucidum can regulate soluble sugar metabolism in three summer–autumn black tea varieties, leading to an improvement in their quality. This study has potential practical significance for regulating the flavor quality of summer–autumn tea.

Health Benefits of High Voltage Electrostatic Field Processing of Fruits and Vegetables.

High voltage electrostatic field processing (HVEF) is a food preservation procedure frequently used to produce healthy minimally processed fruits and vegetables (F&V) as it reduces the growth of microorganisms and activates or inhibits various enzymes, thus retarding their natural ripening while preserving and even enhancing native nutritional quality and sensory characteristics. HVEF is one of the various nonthermal processing technology (NTPT) regarded as abiotic stress that can activate the antioxidant system of F&V and can also inhibith spoilage enzymes as, polyphenol oxidase (PPO), lipoxygenase (LOX), pectin methylesterase (PME), polygalacturonase (PG), cellulase (Cel), β-xylosidase, xyloglucan and endotransglycosylase/hydrolase, bringing positive effect on hardness, firmness, colour attributes, electric conductivity, antioxidant compounds, microstructure and decreasing electrolyte leakage (EL), malondialdehyde (MDA) contents and browning degree. This technique can also increase the contents of fructose, glucose, and sucrose and decrease the production of CO2 and H2O2. Additionally, it has been reported that HVEF could be used with other treatments, such as modified atmosphere packaging (MAP) and acidic electrolyzed water (AEW) treatment, to enhance its effects. Future works should deepen on elucidating the activation of the antioxidant systems by applying HVEF of critical enzymes related to the synthesis pathways of phenolic compounds (PC) and carotenoids (Car). Holistic approaches to the effects of HVEF on metabolism based on systems biology also need to be studied by considering the overall biochemical, physical, and process engineering related aspects of this technique.

PGPB Consortium Formulation to Increase Fermentable Sugar in Agave tequilana Weber var. Blue: A Study in the Field.

Agave tequilana Weber var. Blue is used as the primary raw material in tequila production due to its fructans (inulin) content. This study evaluates the formulation of a plant-growth-promoting bacteria (PGPB) consortium (Pseudomonas sp. and Shimwellia sp.) to increase sugars in A. tequilana under field conditions. A total of three doses were tested: low (5 L ha-1), medium (10 L ha-1), and high (15 L ha-1), with a cellular density of 1 × 108 CFU mL-1 and one control treatment (without application). Total reducing sugars (TRS), inulin, sucrose, glucose, fructose, and plant growth were measured in agave plants aged 4-5 years at 0 (T0), 3 (T3), 6 (T6), and 12 (T12) months. Yield was recorded at T12. The TRS increased by 3%, and inulin by 5.3% in the high-dose treatment compared to the control at T12. Additionally, a low content of sucrose, glucose, and fructose (approximately 1%) was detected. At T12, the weight of agave heads increased by 31.2% in the medium dose and 22.3% in the high dose compared to the control. The high dose provided a higher inulin content. The A. tequilana plants were five years old and exhibited growth comparable to the standards for 6-7-year-old plants. This study demonstrates a sustainable strategy for tequila production, optimizing the use of natural resources and enhancing industry performance through increased sugar content and yield.

High concentrations if fructose and NaCl affect choice behavior in larval drosophila

As a crucial adaptation for survival, the gustatory system serves as a primary mechanism for distinguishing between nutrient-rich compounds that are palatable and those that may pose risks or be unpleasant. This intricate sensory apparatus not only guides behavioral choices but also underpins flavor recognition across various species. Understanding the complexities of the gustatory system in Drosophila larvae has profound implications for unraveling the complexities of human gustatory perception as well as advancing our understanding of sensory processing mechanisms more broadly, thereby providing a broader repertoire of the topic for current days. Behavioral studies employing diverse stimuli have been instrumental in elucidating the underlying processes governing choice, feeding, and learning behaviors in animals. Building upon this foundation, our study sought to explore the specific effects of elevated concentrations of fructose and NaCl on the choice behavior of Drosophila larvae. Through meticulously designed assays using 3M concentrations of fructose and NaCl, we unequivocally demonstrated the pronounced preference of larvae for fructose over NaCl. Furthermore, the robustness of this preference was reaffirmed through a secondary assay employing 3M fructose and water as a control. Our comprehensive findings not only highlight the significant influence of elevated concentrations of fructose and NaCl on larval choice behavior but also shed light on the intricate interplay between sensory perception and genetic mechanisms, particularly involving the Gr5a gene. These insights contribute to our broader understanding of the role of the gustatory system in shaping crucial behaviors vital for animal survival, with potential implications extending to human sensory perception research and beyond.

Whole-genome resequencing identifies candidate genes and allelic variation in the MdNADP-ME promoter that regulate fruit malate and fructose contents in apple

Soluble sugar and organic acids are key determinants of fruit organoleptic quality and directly affect the commodity value and economic returns of fruit crops. We performed whole-genome sequencing of the apple varieties Gala and Xiahongrou, along with their F1 hybrids, to construct a high-density bin map. Our quantitative genetic analysis pinpointed 53 quantitative trait loci (QTLs) related to 11 sugar and acid traits. We identified a candidate gene, MdNADP-ME, responsible for malate degradation, in a stable QTL on linkage group 15. Sequence analysis revealed an A/C SNP in the promoter region (MEp-799) that influences binding of the MdMYB2 transcription factor, thereby affecting MdNADP-ME expression. In our study of various apple genotypes, this SNP has been demonstrated to be linked to malate and fructose levels. We also developed a dCAPS marker associated with fruit fructose content. These results substantiate the role of MdNADP-ME in maintaining the equilibrium between sugar and acid contents in apple fruits.

Comparative Studies of Bioactivities and Chemical Components in Fresh and Black Garlics.

To investigate the bioactivities of fresh garlic and its processed product, black garlic, we conducted comparative analyses of antioxidant, anti-inflammatory, innate immune activation, and anti-cancer activities in addition to the chemical composition (sugar, amino acid, and polyphenol contents) of these materials. Simultaneous assay using neutrophil-like cells showed that fresh garlic exhibited antioxidant and innate immunostimulatory activities, whereas black garlic displayed a potent anti-inflammatory effect. The antioxidant activity index was correlated with phenol and flavonoid contents, while the innate immunostimulatory activity was correlated with fructan content. Furthermore, some black garlics with low fructose content were found to inhibit the proliferation of UM-UC-3 cancer cells, while other black garlics rich in fructose increased UM-UC-3 cell proliferation. It was shown that the processing of fresh garlic could change the composition of sugars, antioxidants, and amino acids, which have different effects on neutrophil-like cells and UM-UC-3 cells, as well as on bioactivities.

Effect of foliar applications of aminolevulinic acid (bulk and nano-encapsulated) on bell pepper under heat stress

Plant growth and production can be adversely affected by high temperature stress, which is defined as an increase in temperature over a threshold level. 5-aminolevulinic acid (ALA) can be used as a beneficial growth regulator in agriculture, particularly for plants experiencing abiotic stress. The efficacy of exogenous two form ALA application (bulk and nanoencapsulated) was investigated in a factorial experiment based on a completely randomized block design with 12 replications. In this study, different temperatures (optimal temperature 25 °C, and high temperature 35 °C) and different ALA treatments were used (control, 1 mM of ALA, and 1 mM Nano-encapsulated N-ALA). The study revealed that elevated temperatures of 35 °C had an adverse impact on the majority of bell pepper growth characteristics. Nevertheless, the application of ALA and N-ALA significantly enhanced the growth characteristics under these conditions. In contrast to the conditions at 25 °C, the concentrations of potassium (K), proline, electrolyte leakage (EL), glucose, and fructose exhibited an increase at 35 °C. However, both forms of ALA were effective in mitigating these adverse effects. Comparatively, the control treatment showed elevated levels of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) enzymes, along with increased malondialdehyde (MDA) levels compared to the ALA treatment. The treatment with ALA resulted in the highest fresh weight and shoot length at 35 °C compared to N-ALA. Conversely, at the same temperature, N-ALA led to a 17 % increase in chlorophyll fluorescence and a 32 % increase in DPPH compared to ALA. In summary, the application of both ALA and Nano-encapsulated N-ALA effectively mitigates the adverse effects of exposure to 35 °C on bell pepper growth and biochemical parameters.

Essential oils combat Botrytis cinerea in apples: unveiling sugar, vitamin, and antioxidant dynamics

AbstractThis study investigated the effects of individual and combination applications of EOCs against Botrytis Cinerea in apple fruits, with a focus on sugar, vitamin, and antioxidant enzyme dynamics. In protective and curative treatments, sucrose content varied between 18.9 and 87.9 g.L-1, with the “CT” group exhibiting significantly higher sucrose levels (87.9 g.L-1). Glucose content ranged from 6.2 g.L-1 (“CT” and “C + F”) to 35.5 g.L-1 (“T + C + E + F”). Fructose content varied significantly, with the “F + T + C + E” treatment showing the highest (11.4 g.L-1) and the “CT” group the lowest (2.5 g.L-1). Rhamnose content in the curative treatment reached 14.9 g.L-1 (“F + T”) and in the protective treatment, the “C + E + F” group had the highest (3.3 g.L-1). Galactose content ranged from 0.1 to 13.0 g.L-1. Xylose content in curative treatment ranged from 12.1 to 13.6 g.L-1, with the combination “F + T” displaying the highest. In preventive treatment, arabinose content ranged from 0.7 to 3.0 g.L-1, with the “T + C + F” group having the highest. In terms of vitamins, the combination “T + F” showed the highest B1 (25.4 mg.100 g-1) and B2 (24.6 mg.100 g-1) content. Vitamin A, B1, and B2 increased in the “F + T” group, and vitamin C increased in the “F + T + C” group (33.4 mg.100 g-1). The quantification of oxidative stress markers and antioxidant enzymes revealed significant reductions in H2O2, MDA, and proline levels in EOC applications. In preventive treatment, the combination “T + C + E + F” exhibited the most effective improvement in SOD activity (556.5 EU mg-1 ), CAT activity increased significantly in the “T + C + F” group (189.3 EU mg-1), and APX activity saw the highest increase in the “T + C + E + F” group (185.6 EU mg-1). Contrastingly, curative treatments showed higher H2O2, MDA, and proline levels. The most significant decrease in H2O2 level occurred in the “T + C + E + F” group (36.7 nmol.g-1), and a significant decrease in MDA level was noted in the same group. Notable changes were observed in the activities of antioxidant enzymes, with the “F + T + C + E” group displaying the highest SOD activity (440.7 EU mg-1), and the “F + T” group showing the highest GST activity (542.0 EU mg-1). This research provided comprehensive insights into the biochemical responses of apple fruits to EOC treatments, offering potential strategies for effective fungal management in agriculture.

Red LED light affects the physicochemical responses of strawberries during storage

This study aimed to evaluate the effect of the storage of strawberries under LED lights on ‘Albion’ strawberry quality. The treatments were applied as follows; (1) storage under continuous blue, red, and ultraviolet-A (UVA) LED light, (2) storage in the dark conditions (control), and (3) storage in the dark conditions after 1 h UVA (UVAh) LED lighting. Strawberries were stored at a temperature of 4±1oC with 85-90% relative humidity for 10 days. In the study, analyses were conducted on the total anthocyanin content, color (L*, hue angle, redness index), total soluble solids (TSS), fructose, glucose, total sugar content, titratable acidity (TA), fruit firmness (N), and weight loss at the start of the experiment and at 2-day intervals during storage. According to the results, the storage of strawberries under continuous red-LED light was successful in improving the anthocyanin and TSS contents, while preserving fruit firmness and reducing weight loss. Moreover, UVA treatment was effective in maintaining the L*, a*, and b* color values, whereas UVAh was effective on the hue angle and redness index. Furthermore, UVAh treatment caused a decrease in the glucose, fructose, and total sugar content and, in the titratable acidity of the strawberries.

Shading Treatment Reduces Grape Sugar Content by Suppressing Photosynthesis-Antenna Protein Pathway Gene Expression in Grape Berries.

To explore the impact of shade treatment on grape berries, 'Marselan' grape berries were bagged under different light transmission rates (100% (CK), 75% (A), 50% (B), 25% (C), 0% (D)). It was observed that this treatment delayed the ripening of the grape berries. The individual weight of the grape berries, as well as the content of fructose, glucose, soluble sugars, and organic acids in the berries, was measured at 90, 100, and 125 days after flowering (DAF90, DAF100, DAF125). The results revealed that shading treatment reduced the sugar content in grape berries; the levels of fructose and glucose were higher in the CK treatment compared to the other treatments, and they increased with the duration of the shading treatment. Conversely, the sucrose content exhibited the opposite trend. Additionally, as the weight of the grape berries increased, the content of soluble solids and soluble sugars in the berries also increased, while the titratable acidity decreased. Furthermore, 16 differentially expressed genes (DEGs) were identified in the photosynthesis-antenna protein pathway from the transcriptome sequencing data. Correlation analysis revealed that the expression levels of genes VIT_08s0007g02190 (Lhcb4) and VIT_15s0024g00040 (Lhca3) were positively correlated with sugar content in the berries at DAF100, but negatively correlated at DAF125. qRT-PCR results confirmed the correlation analysis. This indicates that shading grape clusters inhibits the expression of genes in the photosynthesis-antenna protein pathway in the grape berries, leading to a decrease in sugar content. This finding contributes to a deeper understanding of the impact mechanisms of grape cluster shading on berry quality, providing important scientific grounds for improving grape berry quality.

Autophagy-regulated ethylene synthesis mediates fruit ripening by affecting the accumulation of lycopene, sugars and organic acids in tomato

Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response. However, the role of autophagy in fruit ripening is largely unknown. Here, we demonstrated that most autophagy-related genes (ATGs) were up-regulated during tomato (Solanum lycopersicum L.) fruit ripening. By using mutants of different autophagy pathway genes (ATG6, ATG10, ATG18a), we revealed that the deficiency of autophagy delayed the ripening of fruit. Compared with wild-type (WT), the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening. We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT, while the content of organic acids showed the opposite trend. Additionally, the negative regulator of ethylene production, APETALA2a (AP2a), interacted with ATG8 through a specific ATG8-interacting motif (AIM) and could be degraded through the autophagy pathway. These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments, sugars and organic acids in tomato.

LEVELS OF CARBOHYDRATES IN SHORT-LIVED STRAIN OF Drosophila melanogaster

Aim. The aim of this study was to investigate the concentrations of key energetic substrates such as glucose, fructose, and trehalose, in control and artificially selected flies shown to have shorter lifespan. Methods. For all experiments flies were maintained on standard yeast-sucrose nutrient medium consisted of 5% sucrose, 5% yeast, 1% agar and 0.18% nipagin as mold growth inhibitor. Experimental line of flies was selected on high-protein diet and previously showed short lifespan. Newly enclosed flies were kept two days for mating and used for measurement of feeding behavior and fecundity. Some flies were frozen at -80 °C for further analysis. Concentrations of glucose, fructose and trehalose were measured by Gas Chromatography/Mass Spectrometry using described protocol and expressed per wet weight. Results. Amount of glucose was significantly higher in experimental flies of both sexes. Male flies had about 70% more free glucose and females for about 45%. These differences were accompanied with higher amounts of trehalose that consist of two molecules of glucose and is a form of glucose storage in Drosophila. Trehalose content in experimental males was 2-fold higher, while in females it was higher for about 1.8-fold. Fructose content was also higher in experimental flies. This carbohydrate is metabolized through glycolysis, providing energy in the form of ATP. Beyond energy production, fructose plays a role in supporting reproductive processes such as oogenesis in females, though measure of fecundity showed no difference. Conclusions. Our results show that despite similar consumption of food and reproduction offspring of artificially selected flies have shorter lifespan. However, this effect can be explained by lower energetic status while flies store more energetic substrates such as glucose, fructose and trehalose.